The Weller WESD51 sets the temp at the tip and mine has done that since I bought it in 2016. A look at a datasheet dates it back to 2006 but it could be older. By definition that means it has to know what the tip temp is. As it heats up the digital display tracks the temp going up.
Digital temp adjustment is different than a sensor that tells you the exact temp at the tip.
Pretty sure any 10+ year old unit is just setting a temp, not telling you the actual temp through a measurement.
The Weller WESD51 sets the temp at the tip and mine has done that since I bought it in 2016. A look at a datasheet dates it back to 2006 but it could be older. By definition that means it has to know what the tip temp is. As it heats up the digital display tracks the temp going up.